The present invention is related to a wind energy plant tower with a tower portion made of a concrete material and a steel-made tubular tower segment, which has on its foot a plurality of connection bores for the connection to the tower portion made of the concrete material.
Wind energy plant towers are frequently made completely from steel, with the exception of a foundation. However, with increasing size of the wind energy plant towers, a very large diameter of the tower is required for sufficient stability, in its lower region in particular. From on a certain diameter, significant difficulties in the manufacture and the transportation of the tower segments occur. This results in a high logistic expense and in high costs.
These difficulties can be avoided by making a lower tower portion from a concrete material. The same can consist of prefabricated parts and be composed at the construction site, or it can be completely made at the construction site by casting. On this tower portion made of a concrete material, an additional steel-made tower portion is set up, which may consist of one or several tubular tower segments. Particular attention has to be paid to the connection of the tower portion made of concrete with the lower end of the steel-made tower portion. Different solutions for this connection are known in the state of the art.
In the variant known from the document EP 1 654 460 B1, the entire contents of which is incorporated herein by reference, a lower portion of the tubular tower segment arranged on the lower end of the steel-made tower portion is cast in into an embedding region of the wall of the tower portion made from concrete when casting the tower portion made of concrete Special anchoring elements are fixedly connected with the steel-made tower segment and are intended to improve the stability of the connection between concrete and steel.
In the document DE 20 2006 009 554 U1, the entire contents of which is incorporated herein by reference, it is proposed to use a steel-made special adapter element, which is cast together with the concrete-made tower. In doing so, the adapter element is essentially annular and it encloses the upper end of the concrete-made tower portion. On the upper side of the adapter element, a tubular steel-made tower segment is fastened via a flange joint.
From the document DE 102 30 273 B3, the entire contents of which is incorporated herein by reference, the use of an adapter element is also known. The same is also annular and is connected on its upper end to a tubular steel-made tower segment via a flange joint. The tower portion arranged below the adapter consists of prestressed concrete, wherein prestressing elements run in the interior of the wall of the lower tower portion and are lead through connection bores of the adapter element. Above the adapter element, the prestressing elements are anchored, so that they pretension the adapter element stably with the concrete-made tower portion.
A similar solution is known from the document DE 101 26 912 A1, the entire contents of which is incorporated herein by reference, wherein here, either a separate steel-made adapter element or a suitably shaped lowermost steel-made tower segment is pretensioned with the prestressing elements of the concrete-made tower portion. As a peculiarity, the prestressing elements are arranged inside the tubular shaped concrete-made tower portion.
It is common to all the described realisations that the steel-made tower segment or a separate adapter element is cast together with the concrete-made tower portion or is prestressed with the prestressing elements for the concrete-made tower portion.
Based on this, it is the objective of the present invention to provide a wind energy plant tower which can be erected, serviced and as the case may be repaired more simply and with lower cost, as well as a method for the erection of such a tower.